Backgrounds Exposure to heat is widely used as a traditional therapy in many cultures. Recent studies have shown that thermal therapy by means of warm-water baths and sauna has beneficial effects in chronic heart failure. But warm-feet bath has generally been considered inappropriate for patients with coronary artery disease. However, a comprehensive investigation of the hemodynamic effects of thermal vasodilation on coronary artery has not been previously undertaken. In this study we tried to show the effect of warm feet bath on coronary artery in normal control.Methods We studied 15 patients (100 % men, mean age 30.0 짹 1.4 years) without any cardiovascular risk factors. They were performed coronary flow Doppler examination of left anterior descending coronary artery and placed in a warm feet bath, in which the temperature was evenly maintained at 40째C for 30 min, and then immediately were performed coronary flow doppler examination again. Results With warm feet bath, no significant difference in basal echocardiographic data and coronary flow was observed (diastolic peak flow velocity : 30.05 짹 8.34 cm/min initial, 27.98 짹 10.09 cm/min follow up, p = 0.51, diastolic mean flow velocity : 21.65 짹 5.72 cm/min initial, 21.33 짹 7.92 cm/min follow up, p = 0.89). Systolic and diastolic blood pressure did not change and heart rate was slightly increased without significance. The warm feet bath was well accepted and no relevant adverse effects were observed. Conclusions Coronary flow Doppler did not change after feet immersion to hot water in normal control. Thus, warm feet bath can be applied with little risk of coronary artery event if appropriately performed.